Gold(I)-catalysed cascade reactions in the synthesis of 2,3-fused indole derivatives

A gold(I)-catalysed hydroaminative/arylative cascade for the efficient synthesis of a variety of indole-fused skeletons has been developed. Factors controlling the catalyst loading required in these transformations involving 1,3-unsubstituted indole intermediates have been revealed, allowing isolation of an unprecedented 1,3-dimetallated 3H-indole gold complex characterized by X-ray diffraction.